When I move, you move: Associations between automatic and person-coded measures of infant-mother synchrony during free-play using virtual in-home data collection.

The relationship between movement synchrony and global scores of behavioral synchrony were investigated during a naturalistic free-play between 33 infants (ages 12- to 24-months) and their mothers using a video-conferencing platform. We assessed movement synchrony by applying an automatic tool, motion-energy analysis (MEA), to the obtained video data. Dyadic movement synchrony was associated with higher levels of maternal sensitivity, infant involvement, dyadic reciprocity, and a child-led interaction pattern. This demonstrates the feasibility of using MEA as an automatic tool for assessing movement synchrony in mother-infant dyads and its application for investigating naturalistic at-home free play sessions in a remote setting.

Classifying interpersonal synchronization states using a data-driven approach: implications for social interaction understanding.

This study presents a data-driven approach to identifying interpersonal motor synchrony states by analyzing hand movements captured from a 3D depth camera. Utilizing a single frame from the experiment, an XGBoost machine learning model was employed to differentiate between spontaneous and intentional synchrony modes with nearly [Formula: see text] accuracy. Our findings demonstrate a consistent pattern across subjects, revealing that movement velocity tends to be slower in synchrony modes. These insights support the notion that the relationship between velocity and synchrony is influenced by the cognitive load required for the task, with slower movements leading to higher synchrony in tasks demanding higher cognitive load. This work not only contributes to the limited literature on algorithms for identifying interpersonal synchrony but also has potential implications for developing new metrics to assess real-time human social interactions, understanding social interaction, and diagnosing and developing treatment strategies for social deficits associated with conditions such as Autism Spectrum Disorder.

Virtual social interactions during the COVID-19 pandemic: the effect of interpersonal motor synchrony on social interactions in the virtual space.

Although the link between motor synchrony and emotional alignment has been extensively studied during face-to-face interaction, the question of whether this association also exists in virtual settings has remained unanswered. Here, we examined whether this link exists during virtual social interactions and whether pro-social effects will be induced during those interactions. To this end, two strangers shared difficulties they have experienced due to the COVID-19 pandemic during a virtual social interaction that included both audio and video. The findings revealed that motor synchrony and emotional alignment can arise spontaneously during a virtual social interaction between two strangers. Moreover, this interaction yielded a decrease in negative affect and an increase in positive affect, as well as an increase in feelings of trust, liking, cohesion, self-other overlap, and similarity between the strangers. Finally, a higher level of synchrony during the virtual interaction was specifically associated with increased positive emotional alignment and liking. It can thus be presumed that virtual social interactions may share similar characteristics and social effects as face-to-face interactions. Considering the tremendous changes the COVID-19 pandemic has caused regarding social communication, these findings may provide grounds for developing new intervention protocols aimed at dealing with the consequences of social distancing.

The association between symptom severity and theory of mind impairment in children with attention deficit/hyperactivity disorder.

The aim was to investigate the correlation between ADHD symptom severity and impairments in "theory of mind" (ToM) and empathy, and the improvement in these functions following the administration of methylphenidate (MPH). Fifty children aged 6-12 years with ADHD participated in the study. Symptom severity was assessed using the Swanson, Nolan and Pelham Questionnaire-IV (SNAP-IV). ToM performance was assessed using the "ToM test" and the "Faux-Pas Recognition Test". A significant negative correlation was found between the SNAP-IV Conners index, the oppositional and deportment subscales, and ToM test scores. MPH administration improved ToM scores in a magnitude that was negatively correlated with baseline performance. Additionally, Children with more severe behavioral problems showed greater improvement in ToM following administration of MPH. We conclude that severity of ADHD symptoms, most notably behavioral symptoms, is correlated with deficits in ToM. Administration of MPH improves ToM performance, with the greatest improvement occurring in children with more severe behavioral symptoms.

Lack of association between severity of ADHD symptoms and salivary oxytocin levels.

Impairments in the reactivity of Oxytocin (OT) system were associated with interpersonal difficulties in children with ADHD. The current study aimed to explore the correlation between symptoms severity and salivary OT levels at different time-points in children with ADHD. Symptoms severity was assessed in 50 children with ADHD (28 males, mean age 9.42 ± 1.65) using the Swanson, Nolan and Pelham Questionnaire-IV (SNAP-IV) and the Strengths and Difficulties Questionnaire (SDQ). Salivary OT levels were measured at baseline, as well as 15 min after positive social interaction. There was no statistical correlation between severity of ADHD and salivary OT levels in each of the time points. We conclude that impairments in the reactivity of the OT system in children with ADHD, associated with interpersonal impairments, might be a distinct aspect of the clinical picture, differentiated from the levels of inattentive, hyperactive/impulsive or behavioral symptoms.

High-gamma oscillations as neurocorrelates of ADHD: A MEG crossover placebo-controlled study.

Attention Deficit Hyperactive Disorder (ADHD) is a common neurobehavioral disorder with a significant and pervasive impact on patients' lives. Identifying neurophysiological correlates of ADHD is important for understanding its underlying mechanisms, as well as for improving clinical accuracy beyond cognitive and emotional factors. The present study focuses on finding a diagnostic stable neural correlate based on evaluating MEG resting state frequency bands. Twenty-two ADHD patients and 23 controls adults were blindly randomized to two methylphenidate/placebo evaluation days. On each evaluation day state anxiety was assessed, a 2N-back executive function task was performed, and resting state MEG brain activity was recorded at three timepoints. A frequency-based cluster analysis yielded higher high-gamma power for ADHD over posterior sensors and lower high-gamma power for ADHD over frontal-central sensors. These results were shown to be stable over three measurements, unaffected by methylphenidate treatment, and linked to cognitive accuracy and state anxiety. Furthermore, the differential high-gamma activity evidenced substantial ADHD diagnostic efficacy, comparable to the cognitive and emotional factors. These results indicate that resting state high-gamma activity is a promising, stable, valid and diagnostically-relevant neurocorrelate of ADHD. Due to the evolving understanding both in the cellular and network level of high-gamma oscillations, focusing future studies on this frequency band bears the potential for a better understanding of ADHD, thus advancing the specificity of the evaluation of the disorder and developing new tools for therapy.

Alexithymia and reaching group consensus.

One characteristic of human nature is the ability to align our behavior with others. Previous research has linked poor communication skills to alexithymia. This may suggest the possibility that individuals with high alexithymia do not adhere to the principles of social alignment. One form of cognitive alignment is consensus with a group. So far, little research attention has been given to the possible link between alexithymia and this form of cognitive social alignment. In this study, we address this gap by investigating the association between consensus-reaching abilities and alexithymia. A sample comprising of 122 participants completed the Toronto Alexithymia Scale and then played a specially designed game called "Consensus under a deadline". In each game, a participant played with either seven bots designed to act rationally and always seek a consensus, or with seven other participants. The participants were unaware who they were playing with. The results of the study confirm the link between alexithymia and impaired cognitive social alignment, showing that the alexithymia cognitive component (EOT) is associated with a deficit in reaching a consensus with humans (that sometimes act irrationally). However, this association was not evident when group members were bots (that always act rationally).

Correction: The effect of methylphenidate on social cognition and oxytocin in children with attention deficit hyperactivity disorder.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

What Guides Us to Neurally and Behaviorally Align With Anyone Specific? A Neurobiological Model Based on fNIRS Hyperscanning Studies.

An emerging body of hyperscanning functional near-infrared spectroscopy (fNIRS) research shows interbrain neural synchrony (IBS) during different forms of social interaction. Here we review the recent literature and propose several factors that facilitate IBS, leading us to ask the following question: In a world full of people and opportunities to synchronize with them, what directs our neural and behavioral alignment with anyone specific? We suggest that IBS between what we deem the "mutual social attention systems" of interacting partners-that is, the coupling between participants' temporoparietal junctions and/or prefrontal cortices-facilitates and enhances the ability to tune in to the specific interaction, its participants and its goals. We propose that this process is linked to social alignment, reinforcing one another to facilitate successful and lucrative social interactions. We further suggest that neurochemical mechanisms of dopamine and oxytocin underlie the activation of this suggested loop. Finally, we suggest possible directions for future studies, emphasizing the need to develop a brain-to-brain neurofeedback system with IBS between the mutual social attention systems of the participants as the direct regulating target.

The effect of methylphenidate on social cognition and oxytocin in children with attention deficit hyperactivity disorder.

The current study aimed to explore the possible effect of stimulants on oxytocin (OT), a neuropeptide which regulates social behavior, as a mediator of the pro-social effect of methylphenidate (MPH) in children with attention deficit hyperactivity disorder (ADHD) compared to healthy controls (HCs). Utilizing a double-blind placebo-controlled design, we compared the performance of 50 children with ADHD and 40 HCs in "theory of mind" (ToM) tasks and examined the effect of a single dose of MPH/placebo on ToM and salivary OT levels in children with ADHD at baseline and following an interpersonal interaction. Children with ADHD displayed significantly poorer ToM performance; however, following MPH administration, their performance normalized and differences between children with ADHD and HC were no longer found. Salivary OT levels at baseline did not differ between children with ADHD and HCs. However, after a parent-child interaction, OT levels were significantly higher in the HC group compared to children with ADHD. Administration of MPH attenuated this difference such that after parent-child interaction differences in OT levels between children with ADHD and HC were no longer found. In the ADHD group, OT levels decreased from administration of placebo to the parent-child interaction. However, the administration of MPH to children with ADHD was associated with an increase in OT levels after the parent-child interaction. We conclude that OT might play a role as a mediator of social deficits in children with ADHD and that the reactivity of the OT system to social interaction in children with ADHD might be impaired. Stimulants may improve ToM and social functions in children with ADHD via its impact on the OT system. PRS: OT and Social Cognition in Children with ADHD: Impact of MPH.

A Time-Varying Measure of Dyadic Synchrony for Three-Dimensional Motion.

We propose a novel approach to the analysis of synchronized three-dimensional motion in dyads. Motion recorded at high time resolution, as with a gaming device, is preprocessed in each of the three spatial dimensions by spline smoothing. Synchrony is then defined, at each time point, as the cosine between the two individuals' estimated velocity vectors. The approach is extended to allow a time lag, allowing for the analysis of leader-follower dynamics. Mean square cosine over the time range is proposed as a scalar summary of dyadic synchrony, and this measure is found to be positively associated with cognitive empathy.

Herding Brains: A Core Neural Mechanism for Social Alignment.

When we clap our hands in synchrony, feel the sadness of a friend, or match our attitudes to peer norms, we align our behavior with others. We propose here a model that views synchronized movement, emotional contagion, and social conformity as interrelated processes that rely on shared neural networks. Building on the predictive coding framework, we suggest that social alignment is mediated by a three-component feedback loop - an error-monitoring system that reacts to misalignment, an alignment system, and a reward system that is activated when alignment is achieved. We describe herding-related syndromes (autism, loneliness) and call for innovative research to investigate the links between the levels of alignment.

Theory of Mind and Empathy in Children With ADHD.

Objective: The current study compared empathy and theory of mind (ToM) between children with ADHD and healthy controls, and assessed changes in ToM among children with ADHD following administration of methylphenidate (MPH). Method: Twenty-four children with ADHD (mean age = 10.3 years) were compared with 36 healthy controls. All children completed the interpersonal reactivity index (IRI), a self-reported empathy questionnaire, and performed the "faux-pas" recognition task (FPR). Children with ADHD performed the task with and without MPH. Results: Children with ADHD showed significantly lower levels of self-reported empathy on most IRI subscales. FPR scores were significantly lower in children with ADHD and were improved, following the administration of MPH, to a level equal to that found in healthy controls. Conclusion: Children with ADHD show impaired self-reported empathy and FPR when compared with healthy controls. Stimulants improve FPR in children with ADHD to a level equal to that in healthy controls.

The role of the inferior frontal gyrus in vicarious social touch: A transcranial direct current stimulation (tDCS) study.

The neural mechanisms facilitating the experience of vicarious social touch are largely unknown. The right inferior frontal gyrus (rIFG) has been suggested as part of a simulation observation-execution neural network that plays a key role in the perception of tactile stimuli. Considering that vicarious social touch involves vicarious sharing of emotions, we hypothesized that emotional empathy, i.e., the ability to feel what another individual is feeling, modulates the neural responses to vicarious touch. To examine the role of the rIFG in vicarious touch and its modulation by levels of emotional empathy, we used anodal transcranial direct current stimulation (tDCS) on forty participants who observed photos depicting social touch, nonsocial touch or no touch during tDCS or sham stimulation. The results show that while participants with high levels of emotional empathy exhibited no change in ratings of vicarious social touch, participants with low levels of emotional empathy rate human touch as more emotional following anodal stimulation of the rIFG than following sham stimulation. These findings indicate that emotional responses to vicarious social touch are associated with rIFG activity and are modulated by levels of emotional empathy. This result has major therapeutic potential for individuals with low empathic abilities, such as those with ASD.

The effect of methylphenidate on decision making in patients with borderline personality disorder and attention-deficit/hyperactivity disorder.

Impaired decision making in patients with borderline personality disorder (BPD) has been reported in several studies. Although methylphenidate (MPH) is known to ameliorate impaired decision making in patients with attention-deficit/hyperactivity disorder (ADHD), it has not yet been examined in patients with BPD. We therefore assessed the efficacy of a single dose of MPH on cognitive functions and decision making in patients with BPD. Twenty-two patients diagnosed with BPD participated in the study. The study was a randomized, double-blind placebo-controlled, random block order cross-over trial. Patients participated in two sessions and performed the Test of Variables of Attention, a digit-span test, and the computerized Iowa Gambling Task, after they had been administered either the MPH or a placebo. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale-18. Lower scores on the inattention symptoms scale were associated with a greater improvement in decision making following the administration of MPH when compared with improvements in patients with higher ADHD scores [F(1,17)=5.63, P=0.030]. We conclude that MPH may improve decision making in patients with BPD, although this effect is mediated by the level of ADHD symptoms. Further studies are needed to assess whether a prolonged beneficial effect of MPH on decision making in patients with BPD might also be present in 'real life'.

Novelty-seeking trait predicts the effect of methylphenidate on creativity.

In recent years the use of psychostimulants for cognitive enhancement in healthy individuals with no psychiatric disorders has been on the rise. However, it is still unclear whether psychostimulants improve certain cognitive functions at the cost of others, and how these psychostimulants interact with individual personality differences. In the current study, we investigated whether the effect of one common stimulant, methylphenidate (MPH), on creativity is associated with novelty seeking. Thirty-six healthy adults, without attention-deficit hyperactivity disorder (ADHD) symptomology, were assigned randomly in a double-blind fashion to receive MPH or placebo. We found that the effect of MPH on creativity was dependent on novelty-seeking (NS) personality characteristics of the participants. MPH increased creativity in individuals with lower NS, while it reduced creativity levels in individuals with high NS. These findings highlight the role of the dopaminergic system in creativity, and indicate that among healthy individuals NS can be seen as a predictor of the effect of MPH on creativity.

A possible effect of methylphenidate on state anxiety: A single dose, placebo controlled, crossover study in a control group.

Methylphenidate affects state-anxiety in ADHD patients. The current study examines the effect of Methylphenidate on state-anxiety in healthy subjects. In a cross-over, randomized, controlled, double-blind study, 36 healthy subjects received either Methylphenidate or placebo. As a group, no change in state-anxiety was detected with Methylphenidate. However, participants reporting higher anxiety levels experienced a significant and specific state-anxiety reduction following Methylphenidate. Moreover, a strong negative correlation was found between the initial-level of anxiety and net-change in state-anxiety. These changes were unrelated to self-perceived attention levels. Our results point to the state-dependent effects of Methylphenidate on anxiety.

Attention improves after clinical improvement in acutely depressed adolescents.

In recently depressed adolescents, attention and emotional reactivity improved significantly compared with baseline. Working memory did not improve. This supports the position that, in adolescent depression, attention is state dependent compared with other executive functions that are trait dependent.

Stimulants improve theory of mind in children with attention deficit/hyperactivity disorder.

Impairments in 'theory of mind' (ToM) were linked to social cognition and reciprocal relationships deficits in children with attention deficit/hyperactivity disorder (ADHD). Twenty-four children with ADHD (13 with inattentive type and 11 with combined type, mean age 10.2 years) completed the Interpersonal Reactivity Index (IRI), a self-reported empathy questionnaire. All children performed the 'faux pas' task and a computerized ToM task in two different sessions either with or without administration of methylphenidate (MPH). Administration of MPH was associated with an improvement in cognitive and affective ToM. Children with ADHD-combined type had significantly lower scores in total IRI and the fantasy scale compared to children with ADHD-inattentive type. We conclude that deficits in empathy and ToM may play an important role in the impairments in social cognition and peer relationship in children with ADHD, especially children a hyperactive component. Stimulants may improve ToM and empathic functions. Future studies including larger samples and additional cognitive tasks are warranted in order to generalize these results and to identify possible underlying mechanisms for improvement in ToM following the administration of MPH.